Wireless communication systems, developed to provide communication services while allowing user mobility, are surging in use. The rapid development of technology has brought the system performance up to the level at which various multimedia services can be served wirelessly. As an example of wireless communication services, Long Term Evolution (LTE) proposed by the 3rd Generation Partnership Project (3GPP), is now in service in a number of countries. LTE is a technology for implementing high-speed packet-based communication to provide a transmission speed up to 100 Mbps. LTE, adding various state-of-art technologies, has evolved to a further advanced form offering higher data rates, so-called LTE-Advanced (LTE-A). LTE-A is now in commercial service. Hereinafter, LTE system and LTE-A system are collectively referred to as an LTE system.
Wireless communication systems are recently being developed to support a number of different radio access technologies (RATs). There are various types of RATs, such as, e.g., wireless fidelity (Wi-Fi) offering IEEE802.11x-based wireless local area network (LAN) services, Universal Terrestrial Radio Access Network (UTRAN) providing legacy 3G-based services, and LTE-based Evolved UTRAN (E-UTRAN). User equipments (UEs) such as smartphones, whose use is skyrocketing, basically support multiple RATs. Accordingly, it is critical for the wireless communication system provider to identify what RAT the UE is using so as to process charging and offer policy services in differentiated manners depending on RATs.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.